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High p T identified hadron anisotropic flow and Deuteron production in 200 GeV Au+Au Collisions

High p T identified hadron anisotropic flow and Deuteron production in 200 GeV Au+Au Collisions. Shengli Huang Vanderbilt University for the PHENIX Collaboration. Outline:. Observables and Motivation Analysis methods Results and Discussion ,K,p(pbar) v 2 , v 4

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High p T identified hadron anisotropic flow and Deuteron production in 200 GeV Au+Au Collisions

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  1. High pT identified hadron anisotropic flow and Deuteron production in 200 GeV Au+Au Collisions Shengli Huang Vanderbilt University for the PHENIX Collaboration

  2. Outline: • Observables andMotivation • Analysis methods • Results and Discussion • ,K,p(pbar) v2, v4 • Deuteron production(dbar/d, RCP , B2…) • Conclusions S.L. Huang WWND08

  3. reaction plane beam x y Anisotropic flow v2 and v4 Peter Kolb, PRC 68, 031902 momentum space asymmetry Spatial space asymmetry • Azimuthal correlation with the reaction plane • Built up in the early stage and self-quenched, therefore supply the early information of matter generated in the collision S.L. Huang WWND08

  4. Partonic Flow PHENIX,PRL. 99, 052301 (2007) baryon meson • Baryon and meson elliptic flow follow the number of constituent quark scaling as a function of KET. This indicates that partonic flow builds up at RHIC • How about the higher order anisotropic flow such as v4? • Where is the break point where the hydro interfaces with jet fragmentation S.L. Huang WWND08

  5. Star Preliminary V4/(v2)2 ratio • v4 /v22 is a probe of ideal • hydro behavior and related to • the degree of thermalization! • Peter Kolb, PRC 68, 031902 • R.S.Bhalerao et.al PLB 627,49; • Borghini and Ollitrault, PLB642,227 • Hydro dynamics predicts • v4 /v22 ~0.5 • The identified particles • v4/v22 ratio should provide more • detailed information than • that of charged hadron Y.T. Bai QM06 S.L. Huang WWND08

  6. Recombination module • Large baryon/meson ratios, a factor of 3 above standard fragmentation • The data prefer to the particle production by the recombination in the intermediate pT • The deuteron will supply more information to check the recombination module S.L. Huang WWND08

  7. PHENIX in Run 7 • Run 7: • ~5.5B events and around 50% have been used • A new Time of Flight detector (TOFw) has been installed in • the west arm of PHENIX • A new reaction plane detector (RxNP) has been installed in • the 38 cm < |z| < 42 cm alone the beam S.L. Huang WWND08

  8. TOFw and Aerogel Detectors • TOFw intrinsic timing resolution is ~ 75ps • /K can be separated to 2.8 GeV/c , K/p can be separated • to 4.5 GeV/c and deuteron can be identified to 6~7GeV/c • 3. Together with Aerogel detector(ACC), we can identify the K to • pT~4 GeV/c and , p to 7 GeV/c S.L. Huang WWND08

  9. Reaction plane Measurements • RxNP: • Two sets of plastic • scintillators positioned • on either side of the • collision vertex • 12 segments in  • 2 segments in  • 1.0 < || < 1.5 • 1.5 < || < 2.8 • BBC: • 3.1<||<3.9 • Both detectors are away from mid-rapidity. Smaller non-flow effect • on the reaction plane measurements • New RxNP detector resolution is around 74% at mid-centrality S.L. Huang WWND08

  10. KET Scaling of v4 A.Taranenko • The mass ordering has also been observed for v4 • The number of constituent quark scaling holds for v4 when • KET/nq < 1 GeV. This confirms that matter with partonic degrees • of freedom has been generated at RHIC S.L. Huang WWND08

  11. V4/(v2)2 ratio • The ratio of v4/(v2)2 is close to • 0.9 for the , K and p • Mesons and baryons have similar • v4/(v2)2 ratio What can we extract from this? S.L. Huang WWND08

  12. Perfect Partonic Liquid Partons just in similar momentum space can recombine with each other Mesons and baryons have equal v4/(v2)2 Meson Baryon a) Perfect Partonic Liquid! L.W. Chen, C.M. Ko nucl-th 0602025 b) Partons in different momentum space also can recombine with each other S.L. Huang QM08

  13. Charged  v2 • Charged  v2 can be measured to • 6 GeV/c. • The results are consistent with • 0 results in the overlap pT region. • All  v2 start to drop at pT ~ 2.5 GeV/c • in the different centrality bins! S.L. Huang WWND08

  14. Kaon and Proton v2 • Kaon v2 can be measured to 4 GeV/c and protons v2 can be measured to 6 GeV/c • Proton v2 starts to drop at pT ~ 4 GeV/c S.L. Huang WWND08

  15. Break Point? KET/nq(GeV) KET/nq(GeV) • In the centrality of 20~60%, the , K and p KET scaling seemingly begins to • break at KET/nq ~ 1 GeV • More statistics are required for the further investigation S.L. Huang WWND08

  16. Deuteron pTSpectra H. Valle QM08 The deuteron and anti-deuteron yield have been measured to pT~5 GeV/c in difference centrality S.L. Huang WWND08

  17. dbar/d ratio vspT • Similar to pbar/p ratio, no pT and centrality dependence has been observed for the dbar/d ratio • The dbar/d ratio is 0.46±0.01(stat)±0.05(sys) and p/bar is 0.73 ± 0.01 • The dbar/d ratio is close to the (pbar/p)2 S.L. Huang WWND08

  18. Deuterons Rcp The deuteron RCP peaks at pT~3~3.5GeV/c with the value around 2.8 S.L. Huang WWND08

  19. Coalescence Parameter B2 pd = 2pp • The B2 of d and dbar as a function of pT in difference centrality • B2 increases from central to peripheral collisions • B2 rises with pT S.L. Huang WWND08

  20. B2 and System Volume • Significant change in B2 from 14.5 to 60 Npart • 1/B2 vs Npart shows a consistent linear rise S.L. Huang WWND08

  21. Centrality dependence of Source size Phys.Rev.Lett.93, 152302 (2004) • Radii shows linear increase as the cubic root of the number of participants (Npart) • Consistent with HBT radii for pions. S.L. Huang WWND08

  22. Conclusions New time of flight detector(TOFw) of PHENIX runs successfully in Run 7 with 75 ps intrinsic timing resolution. With new TOFw, we have measured the identified charged hadrons v2 to pT~6 GeV/c, v4 to 4GeV/c and deuteron spectra to 5GeV/c The number of constituent quark scaling has been observed for v4 for KET/nq < 1 GeV. Mesons and bayrons have similar v4/(v2)2 ratio which is close to 0.9 The number of constituent quark scaling seemingly begins to break for v2 as KET/nq~1GeV at 20~60% centrality The d/dbar ratio has no pT and centrality dependence and the deuteron Rcp peaks at pT~3~3.5GeV/c with the value around 2.8 The coalescence parameter (B2) and source radius extracted from deuteron production indicate that the source radius decreases with pT but increases linearly with Npart1/3, which is consistent with expanding source S.L. Huang WWND08

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